MXPA00008186A

MXPA00008186A - Spade blade drill and method of making.

Info

Publication number: MXPA00008186A
Application number: MXPA00008186A
Authority: MX
Inventors: Bruce Dewald A Jr
Original assignee: Kennametal Inc
Priority date: 1999-08-18
Filing date: 2000-08-18
Publication date: 2002-03-15
Also published as: CN1125698C; FR2797599A1; GB2355219A; GB2355219B; CA2316151A1; FR2797599B1; CN1285252A; US6371702B1; CA2316151C; GB0020068D0

Abstract

A spade blade drill having blended open notch forms on either side of an apex. The notches transition into elliptical flutes which extend outwardly toward sides of the insert. The elliptical flute profiles inhibit chip curling and packing. The sides incorporate a pair of surfaces having a reduced clearance angle for preventing chip packing. The blended open notches are deep and extend across the entire width of the flutes, enhancing heat transfer surface area and allowing chips to flow along the entire flute surfaces. A plurality of chip splitters extends from the flutes across two relief surfaces. The chip splitters have a rounded profile, inhibiting chips from becoming hung in the splitters.

Description

SWORD OF SHEET OF SWORD AND METHOD TO MANUFACTURE IT FIELD OF THE INVENTION The present invention relates generally to cutting tools for drilling holes, and more particularly to a bit tip geometry such as in a blade blade bit, and to its method of manufacture.

BACKGROUND OF THE INVENTION Sword blade bits are generally known in the art and use replaceable blade blade inserts to form the cutting edges of the tip of the bit. Conventional inserts or sheets may incorporate slits that thin the core on either side of the tip of a sheet. The recesses lead to grooves. Conventional inserts can use primary and secondary relief surfaces to reduce or eliminate the chisel. Slots may be provided to separate small fragments, chips or burrs through the relief surfaces. Conventionally, the profile of the separators of small fragments, shavings or burrs is somewhat frustroconical with a generally circular valley. Small variations in the dimensions or arrangement of the geometry of the tip can have a significant affect on the life and performance of the bit.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a sword blade bit having an insert with a combined open slit shape that intersects the back of the attack face and which is generally concave through the slit, rearwardly of the cutting edge, and a length ratio of the lip of the slit to the length of the hook of the controlled slit, which leads to a better evacuation of the small fragments, shavings or burrs, and a reduced heat flow due to an increase in the Surface area of heat transfer. In one aspect of the present invention, the blade blade insert has an angle of incidence or staggering in its planar portions between elliptically profiled grooves and channels and round, open, small profiled chip separators to reduce packing and beading the small fragments. These and other features and advantages of the invention will be more clearly understood from the following detailed description and drawings of the preferred embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a side view in partial section of the tip of a sword blade drill assembly according to a preferred embodiment of the present invention. FIGURE 2 is a side view of the sword blade insert of FIGURE 1. FIGURE 3 is a view from the tip end of the sheet of FIGURE 2. FIGURE 4 is a partial close-up view similar to FIG. FIGURE 3. FIGURE 5 is a partial close-up view similar to FIGURE 2. FIGURE ß is a view taken in the direction of arrow VI of FIGURE 3. FIGURE 7 is a view similar to FIGURE 6 of a characteristic of conventional sheet. FIGURE 8 is a view similar to FIGURE 6 showing a rounded surface K-burnisher. FIGURE 9 is a view similar to FIGURE 6 showing a surface honing machine at nominal K. FIGURE 10 is a view taken in the direction of arrow X of FIGURE 4 showing the spacer of small fragments of the insert.

FIGURE 11 is a view similar to FIGURE 10 of the conventional blade attachment. FIGURE 12 is a view from the end of the amplified tip of the insert of FIGURE 1 showing a rectification angle of the slit. FIGURE 13 is a side view of the insert of FIGURE 1. FIGURE 14 is a perspective view of the insert of FIGURE 1. FIGURE 15 is another perspective view of the insert of FIGURE 1. FIGURE 16 is a view from the tip of the insert tip of FIGURE 1. FIGURE 17 is another side view of the insert in FIGURE 1. FIGURE 18 is a similar view to FIGURE 5.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIGURE 1, there is shown a drill assembly for large diameter drills or sword blade, generally designated by reference numeral 100, according to a preferred embodiment of the present invention. . The drill assembly 100 includes a fastener 101 and a removable blade blade insert, generally designated by the reference numeral 10. The fastener 101 is made of a longitudinally extending rod having a longitudinal axis of symmetry 102 and a body portion or shaft (not shown) dimensioned and shaped to be held by a torsion tool such as a machine tool. The fastener 101 has a cylindrical portion 103 with two channels 109 spirally about the axis 102 and ending at the end of the tip 105 of the cylinder 103. In another embodiment, the channel or channels 109 may be parallel to the axis 102, or straight and no spirals The blade blade insert 10 is received in a slot 104 formed in the end of the tip 105 of the fastener 101. The blade blade insert 10 includes the cutting surfaces for the tip of the drill 100 and is sized and shaped to extend out of the slot 104 in the axial and radial directions to engage and cut the material of the workpiece. A locating pin 108 received in a cavity 104 formed in the lower surface 106 of the slot 104. The pin 108 extends from the cavity towards the slot 104. The sword blade 10 includes a locating cavity 11 formed in its lower side 113 and is dimensioned to engage the locating pin 108 after the insertion of the sheet 10 into the cavity 107. The cavity 11 and the pin 108 are positioned to generally locate the blade 10 while it is inserted in the slot 104. The two threaded fastening and alignment screws 120 extend through the two alignment holes 17 of the blade 10 and engage the "two threaded holes 114 of the fastener 101. The screws 120, the holes 17 and the perforations 114 are dimensioned and formed to align the blade 10 with respect to the shaft 102. In the illustrated embodiment, the bolt 108 is slightly narrower than the cavity 11, so that the blade 10 can be easily loc alized in the groove of the fastener 104 before alignment. In this way, after alignment of the sheet 10 using the screws 120, light spaces 111 remain on one or both of the sides of the pin 108. In the event that the sheet 10 is subjected to extreme lateral forces that tend to move the 10 out of the position in the groove of the fastener 104, the cavities 11 can be moved accordingly to close any space 111 and push the blade 10 against the bolt 108. In this way, the bolt 108 can reinforce the alignment screws 120 against cutting or other damage due to such forces. Although the perforations and the holes are in axial alignment with respect to the axis 102 to thereby align the shaft 49 (Figure 2) of the sheet 10 when the shaft 102, the perforations may be slightly out of longitudinal alignment with the holes, so that when the screws are tightened, the blade 10 is pushed to lay its lower surface 113 against the lower surface 106 of the groove of the fastener 104. The screws 120 and the holes of the blade 17 can be formed with bevelled surfaces mutually engaging , such as the beveled surfaces 117 of the sheet 10 (Figure 2), to aid in assembly and alignment. The alignment arrangement of the illustrated embodiment is advantageous over the other alignment arrangements that use screws to push a blade cavity laterally against a bolt to achieve alignment. In such other arrangements, the screw is continually subjected to lateral shear forces to achieve blade alignment. In this way, when additional extreme lateral forces are experienced, those additional forces can be added to the existing forces. Also the space can be relatively large between the bolt and the blade cavity on the non-engaging side of the bolt. A large space requires more displacement of the blade to close the space before the bolt can reinforce the bolt. Thus, in such alignment arrangements, the screw may be more likely to be damaged due to the extreme lateral shear forces experienced in use. We refer now to Figures 2 and 3, which show the blade blade insert 10 separated from the fastener 101. The blade 10 has a vertex 12, a pair of cutting edges 13, a pair of primary relief surfaces, and a pair of secondary relief surfaces 16, a pair of slits that thin the core 20, and a pair of channels 30. The sheet 10 has a width 116 between the opposite side faces 73 and a leaf diameter 115. The channels 30 are concave and its surface is known as surfaces or faces of attack 31. The intersection of the strike surface 31 and the primary relief surface 14 forms the primary cutting edge 13. The primary and secondary relief surfaces 14 and 16 meet at the apex 12 and extend towards the surfaces or flat portions between the lateral grooves of the insert 50. A plurality of small fragment spacer slots 40 extend from the channels 30 until they interrupt the cutting edges 13 and the ends thereof. relief surfaces 14 and 16. In the embodiment shown, there are 3 straight slots 40 on each side of the vertex 12 and each of the six slots 40 has a unique radial position with respect to the vertex 12. The intersection of the slit 20 and the Primary relief surface 14 is the call of the slit 23. The intersection of the slit 20 and the secondary relief surface 16 is the so-called hook of the slit 21. With reference to the slit 3, in use, the sheet 10 rotates around from its vertex in the direction of the arrow 120. The lip of the slit 23 lies mainly on the leading edge of the sheet 10 during rotation and functions as a cutting edge. The hook 21 enters mainly on the rear side of the sheet 10 during rotation. The intersection of the relief surface 16 and the primary relief surface 14 on the opposite side of the apex 12 forms a leading cutting edge called the secondary cutting edge 32. The cavity of the blade 11 includes curved corner surfaces 118 formed to reinforce the corners of the blade. the cavity 11 against rupture. As shown in Figures 2 and 3, the sheet 10 has a longitudinal symmetry axis 49, a major axis 48, and a minor axis 47, all mutually perpendicular. The major axis 48 is generally parallel to the cutting edge 13 and the side surface of the blade 73. With reference to FIGURE 4, the length of the lip of the slit 22 is the length of the projection of the lip of the slit 23 on the plane of the view paper of FIGURE 4 measured from the axis 47, that is, the plane defined by the axes 47 and 48, and whose projection in turn projects on a plane normal to the plane of FIGURE 4 and parallel to the edge 13, ie, the plane defined by axes 48 and 49. The length of the hook of the slit 24 is the same projection of the hook of the slit 21. It is advantageous to control the ratio of the length of the lip 22 to the length of the hook 2. through a variety of 115 diameter inserts 10. Conventional inserts or sheets generally use a constant hook length and a length of. variable lip, which consequently increases the ratio _ of. length of lip / length of the hook as the diameter of the insert increases. The approximate values for the lip length / hook length ratio for the illustrated embodiment of insert 10 of various diameters compared to conventional inserts are the following: In general, when the ratio of the length of the lip / length of the hook decreases, the chips of the cut material, called small fragments, shavings or burrs, formed by the cutting action of the cutting edges of the lips, become narrower and most likely roll up on themselves. This can cause small fragments of chips or burrs to accumulate at the bottom of the channel, the sheet and accelerate the wear on the face of the blade. This effect may become more pronounced for hook length / hook length ratios of less than about 1. When the lip length / hook length is increased, smaller fragments, chips or larger burrs are produced due to a cutting edge of the lip. relatively larger. However, there is less space for smaller, wider fragments to be removed from the vicinity due to the cutting action of the relatively short hook length. This effect may become more pronounced for hook length / hook length ratios greater than about 1 and a third. Preferably, for the illustrated embodiment, the length ratio of the lip / hook length should be from about 1 to about 1.33 and more preferably from about 1.05 to about 1.2. One aspect of the described embodiment, as shown in FIGURE 5, is that the slit 20 has a combined and more open shape than the slits of the conventional sword blade inserts. As illustrated, the slit 20 has a hook length 24 that is greater than the depth of the conventional slits. It is desirable that the slit the length of the hook 24 be greater than or equal to the width of the surface of the strike face 31. Preferably, the length of the hook should be from about 4 to about 6% greater than the width of the face of attack, and can be from about 6 to about 12% greater than the width of the surface of the attack face. Furthermore, the slit 20 is defined by a variable curvature or a combination of curvatures, referred to as a combination, to increase its length so that it completely crosses the channel 30. Mixing can be achieved through one or more rectification phases during manufacturing of the insert 10. Mixing and making the slit 20 more open through increasing its depth 26 increases the evacuation of small fragments. In addition, the small fragments can be wound through a larger surface area, increasing the heat transfer surface area, thereby reducing the heat flow in the slit 20 (which can in other circumstances cause premature thermal failure of the insert 10). under high speed conditions). Finally, by enlarging the slit 20, small fragments, chips or burrs are allowed to flow along the entire face of the channel 30. In the embodiment illustrated in FIGURE 4, the planes containing the lip edges of the slit 23 they are parallel to each other on either side of the vertex 12. The angle between the edge 23 and the edge 13 is the so-called angle of the core 17. A core 19 has a web width 18 which constitutes the perpendicular distance between the edges of the lip 23. The width of the web 18 of the illustrated embodiment is generally smaller than conventional web widths. A thinner soul 19 produces certain benefits, including increasing the penetration speed of the insert 10, allowing deeper holes to be drilled, and decreasing horsepower consumption due to a lower thrust. In addition, the accessibility of the insert 10 is widened to allow use with tools having a lower nominal power, "j. in other words they would be under-energized for conventional sword blades. The approximate values for the nominal width 18 of the core 19 of the insert 10 for various diameters compared to the conventional sheets are the following: Manufacturing tolerances of the core thickness of the insert 10 is preferably ± .002 inches (0.05 millimeters) for each series of inserts 10. The core thicknesses of the conventional sheets were determined by measuring numerous conventional sheets within each series. Manufacturing tolerances of conventional sheets are such that 95% or less of conventional sheets are within about ± .003 (0.076 millimeters) of thickness for each series. Accordingly, the average reduction in the thickness of the web 18 of the insert 10 of the illustrated embodiment and the conventional sheets is approximately 10% for each series. With reference to FIGURES 12 and 18, another aspect of the described embodiment is a reduced slit rectification angle 28. In addition, the angle of rectification of the slit varies with the diameter of the sheet 10 or the series of sheets 10. The angle of rectification of the slit 28 is determined in relation to an angle of inclination 25 and an angle of the apex 27. The reduction and variation of the angle of rectification of the slit facilitates obtaining the ratio of the length of the lip / length of the hook and obtaining the open combined slit 20 extending towards the back of the attack face. The angle of rectification of the slit for the described embodiment is from about 18 to about 25 degrees and can be adapted to achieve the shape of the desired slit. The approximate values for the angle of rectification of the nominal slot of the insert 10 for various diameters compared to conventional sheets are as follows: To determine the rectification angle of the slit 28, rotate FIGURE 4 of the insert 10 around its apex 12 ninety degrees. Next, rotate the vertex 12 clockwise an angle equal to the angle of the apex 27 and the angle of inclination 25 (FIGURE 13). The corner angle 27 is approximately 132 degrees for the illustrated mode. The "inclination angle 25" is the angle at which the slit 20 is ground in relation to the angle of the apex 27, but in the plane of the rectification angle of the slit 28. In the plane of the rectification angle of the slit 28, the The angle of inclination of the slit 25 has a value of approximately 7 degrees, while the angle of inclination 25 is approximately 9 degrees measured relative to one of the flat surfaces of the sheet 10. After rotating the vertex 12 in the clockwise an angle equal to the angle of the apex 27 and the angle of inclination 25, rotate the insert 10 in a direction towards the page until the rectification lines 29 (FIGURE 12) are horizontal with respect to a set of transverse strands defined within a laboratory reference frame The angle between the rectification line 29 and the projected, but rotated, sides of the sheet 10 define e the angle of rectification of the slit 28. The angle of rectification of the slit 28 depends on the interval (series) of the diameter of the insert 10, as opposed to the conventional sheets which incorporate a rectification angle of the constant slit. Preferably, the angle of rectification of the slit is approximately 20 degrees. The optimum slit 20 for the evacuation and control of small fragments, shavings or burrs is not included by the diameter of the sheet 10, that is to say, that the shape of the slit is maintained on all the diameters of the inserts 10. The method for manufacturing a slit 20 is an iterative process which is a function of the shape of the wheel, the size of the blade 10, the width of the channel 30, sustaining the relationship of the length of the lip / length of the hook, and ensuring that the shape of the slit 20 is generally concave rearwardly of the cutting edge 13. Next, the method for manufacturing a mixed slit 20 will be described with reference to Figures 13 to 17. With the sheet 10 in the position as shown in Figure 13, the side 50 shown is rotated downwardly by the angle 70, as shown in Figure 14. Next, the rear face 73 of the insert 10 is rotated in the clockwise direction by an angle 72 (Figure 15) . With the insert 10 in the position shown in Figure 16, an abrasive wheel (not shown) grinds down the direction 76 in the angle 74 (Figure 16) to form the slit 20. The insert 10 shows in Figure 16 as if it would have been rotated through the angle 74 only to define the angle between the wheel and the insert 10 as described in Figure 15. During the grinding process, the insert 10 is actually in the position shown in Figure 15. The position of the wheel allows the slit 20 to be combined to form the width of the attack surface (channel 30), as shown in Figure 17 at the tip 12. With specific reference to Figure 3, the lateral surfaces 50 of the insert 10 includes a lip 52, a first lip surface 54 and a second lip surface 56. The angle of attack 58, between the lip surfaces 54 and 56 is smaller than the angle of attack of conventional blades. The conventional blades have an angle of attack of between about 38 and 40 degrees, while the angle of attack 58 of the insert 10 is about 30 degrees. A smaller angle of attack 58 reduces the packing of small fragments, chips or burrs between the body of the sword blade and the side wall of the hole being drilled. Another aspect of the described embodiment, as shown in Figures 6 and 1, is that the channels 30 of the insert 10 have an elliptical channel shape 33, in contrast to a conventional radial channel shape 233 of the sheet 210. The shape Elliptical 33 produces smaller fragments, shavings or flatter and thinner burrs, in contrast to radial shape 233, which can most likely result in the winding and packing of small fragments, chips or burrs. In addition, the channels 30 may have their edges "broken" or ground to prevent fracture of the insert 10 during use. As shown in Figures 8 and 9, a rounded K-surface growler 61 is formed on the edge 13 of the channel 30. The rounded K-surface growler 61 has a width 15 and an angle 60. As shown in FIG. Figure 9, the nominal K-surface growler 63 is formed on the edge of the channel 30. The nominal K-surface growler 63 has a width 15 and an angle 60. The snarl of the cutting edge 13 can increase the life of the tool as described in the US patent No. 5,609,447, incorporated herein by reference. The approximate values for the K-surface growlers of insert 10 for various diameters are as follows: The angle of the surface at K fluctuates from about 0 to about 40 degrees, and more preferably from about 15 to about 25 degrees. Another aspect of the disclosed embodiment is that the small chip, chip or burrs separators 40 of the insert 10 as shown in Figure 10 are wider and rounder in the shape of the cross section through the depth 42 than the sheets. of conventional swords, as shown in Figure 11. The conventional sword blade slit 240 has a profile defined by an angle 245 through a portion of its depth 242 and width 244 and further defined by a relatively narrow radius in your background. A wider and rounder profile decreases the likelihood that small fragments, chips or burrs will stick in the separators of small fragments, chips or burrs 40 themselves and thus add to the life of sheet 10. following examples provide additional support bases for the above description of the insert 10.

EXAMPLE 1 Uncoated 1-1 / 8 inch (2.9 cm) sword blades were tested as follows: Vertical drilling, 80 sfm, .010 inch / revolution (ipr) (0.02 (cpr)), cooling fluid = soluble refrigerant fluid in water 16: 1, blind hole 1.95"(4.95 cm) in Steel 4140 @ Brinell hardness index (Bhn) 280 + 15 A conventional blade produced an average of 56 holes. A sheet having a thinned web 19 and an open combined slit 20, without other characteristic geometric changes described above, i.e., which was otherwise conventional, produced an average of 85 holes. A sheet having the separator of smaller fragments, chips or more rounded burrs 40, without other characteristic geometric changes described above, produced an average of 72 holes.

EXAMPLE 2 1-1 / 2 inch sword blades tested (3.81 centimeters) coated with titanium nitride (TiN) as follows: Vertical drilling, 88 sfm, .008 ipr (0.020 cpr) cooling fluid = 16: 1 water-soluble cooling fluid, steel 4340 @ 285 ± 10 Bhn. A conventional sheet perforated an average of 97 holes. A sheet including all the described geometrical characteristics of the insert 10, with the exception that the ratio of the length of the lip / length of the hook was equal to 1.38 and the sheet lacked the open combined slit shape described, was an average of 75 holes. A blade including all the described geometrical features of the insert 10 produced an average number of 126 holes.

EXAMPLE 3 3/4 inch (1.91 cm) sword blades coated with titanium nitride (TiN) were tested as follows: Vertical drilling, 126 sfm, .008 ipr (0.020 cpr) cooling fluid = 16: 1 water-soluble cooling fluid, 4150 steel @ 285 ± 10 Bhn. A conventional sheet averaged 114 holes. A sheet including all the geometric features described above of the insert 10 averaged 144 holes. EXAMPLE 4 1-1 / 8 inch (2.88 cm) sword blades coated with titanium nitride (TiN) were tested as follows: Vertical drilling, 118 sfm, .016 ipr (0.040 cpr) cooling fluid = water soluble cooling fluid 16: 1, steel 4150 @ 285 ± 10 Bhn. A conventional sheet averaged 114 holes. A sheet including all the geometric features described above of the insert 10, including a surface burnisher at nominal K 63, averaged 186 holes. A sheet that includes all of the geometric features described above of the insert 10, including a surface burnisher at nominal K 61, averaged 216 holes. The surface angle at K 60 was 20 degrees and the width 15 was 0.003 inches (0.076 millimeters) ± .001 (0.025 millimeters).

The described modalities allow an insert that provides higher penetration speeds, lower consumption of horsepower and deeper holes, increasing 'at the same time its accessibility to sub-energized machines. In addition, the described embodiments provide an insert with small chip evacuation, increased chips or burrs, a reduced heat flow due to an increase in heat transfer surface area, and packing and winding of small chips, chips or reduced burrs. The description and the foregoing drawings are only illustrative of the preferred embodiments of the present invention, and are not intended to limit the present invention to these. For example, one embodiment shown has six separating grooves of small fragments, chips or burrs arranged asymmetrically, however the invention is not limited to those arrangements. Also, for example, a described embodiment includes a sword blade mounted on a fastener in a specific manner. However, other mounting arrangements could be used. Any subject matter or modification thereof falling within the spirit and scope of the following claims is considered part of the present invention.

Claims

CHAPTER CLAIMEDICATORÍO Having described the invention, it is considered as a novelty and, therefore, the content is claimed in the following CLAIMS: 1. A large diameter drill bit, characterized in that it comprises: a sword blade fastener having a recessed portion and a bolt on an upper surface of the recessed portion; a sword blade attached to the sword blade holder, the sword blade has a longitudinal cutting shaft and a cavity on a lower surface to accept the bolt; and where the cavity is larger than the bolt, so that when the blade of the sword is mounted on the fastener of the blade of the sword there is at least one longitudinal space between the bolt and the cavity. 2. The sword drill according to claim 1, characterized in that the sword blade has at least one groove that thins the core, at least one groove has a hook edge with a hook length and a lip edge with a hook edge. length of lip, where the ratio of the length of the width to the length of the lip of the slit is from about 1 to about 1 1/3. The sword bit according to claim 2, characterized in that the ratio of the length of the hook to the length of the lip of the slot is from about 1.05 to about 1.20. The sword drill according to claim 1, characterized in that the sword blade has a surface honing machine at K. 5. The sword drill according to claim 4, characterized in that the surface honing machine at K has a angle from about 0 to about 40 degrees. The sword drill according to claim 4, characterized in that the surface honing machine at K has an angle of about 15 to about 25 degrees. 7. The sword drill according to claim 2, characterized in that the slit is formed by mixing. 8. The sword drill according to claim 2, characterized in that the blade of the sword drill has at least one attack surface, the crack is formed in the attack surface. 9. The sword drill according to claim 8, characterized in that the attack surface has an elliptical channel shape. The sword bit according to claim 8, characterized in that the length of the hook of the slot is greater than or equal to the width of the attack face. The sword bit according to claim 8, characterized in that the length of the hook of the slit is from about 4 to about 12 percent greater than the width of the attack face. The sword bit according to claim 8, characterized in that the length of the hook of the slit is from about 4 to about 6 percent greater than the width of the attack face. The sword drill according to claim 8, characterized in that it also comprises at least first and second attack faces and at least first and second slits on the respective attack faces. The sword bit according to claim 13, characterized in that the blade of the sword bit has a web width defined by the distance between the edges of the lip and the first and second slits, the width of the web is approximately 10 mm. percent less than the conventional sword drill blades. 3Q 15. The sword drill according to claim 2, characterized in that the slit has a - Rectification angle of the variable slit that depends "of the diameter of the sword blade bit 16. The sword bit according to claim 15, characterized in that the slit has a grinding angle of the slit from about 18 to about 25 degrees. , characterized in that it comprises: a sword blade fastener; a blade of sword fixed to the sword blade holder, the sword blade has at least one slit that thins the soul, and the slit has a hook edge with a hook length and a lip edge with a lip length; and wherein the ratio of the length of the hook to the length of the lip of the slit is from about 1 to about 1 1/3. 18. The sword drill according to claim 17, characterized in that the ratio of the length of the hook to the length of the lip of the slit is from about 1.05 to about 1.20. 19. The sword drill according to claim 17, characterized in that the sword blade has a surface honing machine in K. 20. The sword drill according to claim 19, characterized in that the surface burnisher at K has an angle from about 0 to about 40 degrees. 21. The sword drill according to claim 19, characterized in that the surface honing machine at K has an angle of about 15 to about 25 degrees. 22. The sword drill according to claim 17, characterized in that the slit is formed by mixing. 23. The sword drill according to claim 17, characterized in that the blade of the sword drill has at least one attack surface, the crack being formed in the attack surface. 24. The sword drill according to claim 23, characterized in that the attack surface has an elliptical channel shape. 25. The sword drill according to claim 17, characterized in that the attack surface is generally concave. 26. The sword drill according to claim 23, characterized in that the length of the hook of the slit is from about 4 to about 12 percent greater than the width of the attack face. 27. The sword drill according to claim 23, characterized in that the length of the hook of the slit is from about 4 to about 6 percent greater than the width of the attack face. The sword drill according to claim 17, characterized in that it further comprises at least first and second attack faces and at least first and second slits on the respective attack faces. 29. The sword drill according to claim 28, characterized in that the blade of the sword drill has a web width defined by the distance between the edges of the lip and the first and second slits, the width of the web is approximately 10 mm. percent less than the conventional sword drill blades. 30. The sword bit according to claim 17, characterized in that the slot has a variable slit angle of rectification that depends on the diameter of the sword blade bit. 31. The sword drill according to claim 17, characterized in that the slot has a grinding angle of the variable slit of about 18 to about 25 degrees which depends on the diameter of the sword blade bit. The sword drill according to claim 17, characterized in that the sword blade holder has a recessed portion and a bolt on an upper surface of the recessed portion, the sword blade has a longitudinal cutting shaft and a recess on a lower surface to accept the bolt, and where the cavity is larger than the bolt so that when the blade of the sword is mounted on the bracket of the sword hoe there is a longitudinal space between the bolt and the cavity. 33. A sword bit, characterized in that it comprises a cylindrical grooved holding portion having a tip end fastener, a sword insert fixed to the tip end fastener, the insert has pointed surfaces formed along the length of the tip. an edge of the tip, the surfaces of the tip include a primary relief surface and a secondary relief surface, the relief surfaces extend from the apex of the edge of the tip to the external diameter of the tip to the external diameter of the tip. insert, a laterally extending channel that forms an attack surface that intersects the primary relief surface to form a primary cutting edge, a slit that thins the formed web through the channel at the apex, the slit is concave through all of its width, the slit is combined to form a concave profile, a plurality of slots separating small fragments, shavings or reba They extend from the channel to interrupt the primary cutting edges and the primary and secondary relief surfaces., the slit has a length of width and a length of lip, the ratio of the length of the lip to the length of the hook is from about one to about one and one third. 34. The sword drill according to claim 33, characterized in that the length of the hook of the slot is greater than or equal to the width of the attack face. 35. The sword drill according to claim 33, characterized in that the length of the hook of the slit is from about 4 to about 12 percent greater than the width of the attack face. 36. The sword drill according to claim 33, characterized in that the length of the hook of the slit is from about 4 to about 6 percent greater than the width of the attack face. 37. A blade of a sword bit, the blade of the sword bit is characterized because it comprises: at least one slit that thins the soul, the slit has a hook edge, the length of the width and a lip edge with a length of lip, wherein the ratio of the length of the width to the length of the lip of the slit is from about 1 to about 1 1/3. 38. The sword drill blade according to claim 37, characterized in that the ratio of the length of the hook to the length of the lip of the slit is from about 1.05 to about 1.20. 39. The sword drill blade according to claim 37, characterized in that the sword blade has a surface growler at K. 40. The sword drill according to claim 39, characterized in that the surface growler in K it has an angle of approximately 0 to approximately 40 degrees. 41. The sword drill according to claim 39, characterized in that the surface grinder at K has an angle of about 15 to about 25 degrees. 42. The sword drill blade according to claim 3, characterized in that the slit is formed by mixing 43. The sword drill blade according to claim 37, characterized in that the sword drill blade has the 44. The sword bit according to claim 43, characterized in that the surface has an elliptical grooved shape, 45. The sword bit in accordance with the claim. 44, characterized in that the attack surface is generally concave 46. The sword drill according to claim 44, characterized in that the length of the hook of the slit is from about 4 to about 12 percent greater than the width of the face. 47. The sword drill according to claim 44, characterized in that the length of the hook of the slit is approximately 4. up to about 6 percent greater than the width of the attack face. 48. The sword drill blade according to claim 37, characterized in that it further comprises first and second attack surfaces and at least first and second slits on the respective attack faces. 49. The sword drill blade according to claim 48, characterized in that the sword drill blade has a web width defined by the distance between the edges of the first and second slits, the width of the web is approximately 10 mm. cent less than conventional sword drill blades. 50. The sword drill blade according to claim 37, characterized in that the recess has a recess angle of the variable recess that depends on the diameter of the spade blade bit. 51. The blade of sword drill according to claim 50, characterized in that the groove has a rectification angle of the slit variable from about 18 to about 25 degrees that depends on the diameter of the bit of the blade blade. 52. The sword drill blade according to claim 37, characterized in that the sword drill blade is mounted on a sword blade fastener. 53. A method for forming a sword drill, the method is characterized in that it comprises the steps of: forming a sword blade fastener having a recessed portion and a bolt on an upper surface of the recessed portion; form a sword blade, the sword blade has a longitudinal cutting shaft and a cavity on a lower surface to accept the bolt, the cavity is larger than the bolt; and assemble the sword blade to the sword blade holder, so that when the sword blade is mounted to the sword blade holder there is a longitudinal space "between the bolt and the cavity 54. The method in accordance with the claim 53, characterized in that it also comprises the step of forming a combined slit on the sword blade. 55. The method of compliance with the claim 54, characterized in that the step of forming the combined slit comprises the step of rectifying the sword blade, so that the ratio of the length of the hook to the length of the lip of the slit is from about 1 to about 1 1/3. 56. The method according to claim 54, characterized in that the step of forming the combined slit comprises the step of rectifying the blade of the sword, so that the ratio of the length of the hook to the length of the lip of the slit is about 1 to about 1 1/3. 57. The method of compliance with the claim 54, characterized in that the step of forming the combined slit comprises the step of rectifying the sword blade, so that the length of the slit hook is from about 4 to about 12 percent greater than the width of the attack face of the slit. the sword blade. 58. The method according to claim 54, characterized in that the step of forming the combined slit comprises the step of grinding the sword blade, so that the length of the slit hook is from about 4 to about 6 percent greater than the length of the slit. width of the attack face of the sword blade. 59. A method for forming a sword drill blade, the method is characterized in that it comprises the steps of: forming a sword blade bit having a combined slit; and mount a sword blade to the sword blade holder. 60. The method according to claim 59, characterized in that the step of forming the combined slit comprises the step of rectifying the sword blade, so that the ratio of the length of the hook to the length of the lip of the slit is about 1 to about 1 1/3. 61. The method of compliance with the claim 59, characterized in that the step of forming the combined slit comprises the step of rectifying the sword blade, so that the ratio of the length of the hook to the length of the lip of the slit is from about 1 to about 1 1/3. 62. The method according to claim 59, characterized in that the step of forming the combined slit comprises the step of rectifying the sword blade, so that the length of the slit hook is from about 4 to about 12 percent greater than the length of the slit. width of the attack face of the sword blade. 63. The method according to claim 59, characterized in that the step of forming the combined slit comprises the step of grinding the sword blade, so that the length of the slit hook is from about 4 to about 6 percent larger. that the width of the attack face of the sword blade.